Windows: Ambient Light API

content/browser/device_sensors/data_fetcher_shared_memory_win.cc

Index: content/browser/device_sensors/data_fetcher_shared_memory_win.cc
diff --git a/content/browser/device_sensors/data_fetcher_shared_memory_win.cc b/content/browser/device_sensors/data_fetcher_shared_memory_win.cc
index c5d24fc75198cd743fbd9ca54070ab9dfcb4c3e4..28582eae8c3fd17904100b013a3b95b33cf0fea4 100644
--- a/content/browser/device_sensors/data_fetcher_shared_memory_win.cc
+++ b/content/browser/device_sensors/data_fetcher_shared_memory_win.cc
@@ -18,6 +18,16 @@ namespace {
 
 const double kMeanGravity = 9.80665;
 
+static bool SetLightBuffer(content::DeviceLightHardwareBuffer* buffer,

[timvolodine, 2015/03/02 17:39:58]

no need for static

[riju_, 2015/03/03 09:53:55]

Done.

+                           double lux) {
+  if (!buffer)
+    return false;
+  buffer->seqlock.WriteBegin();
+  buffer->data.value = lux;
+  buffer->seqlock.WriteEnd();
+  return true;

[timvolodine, 2015/03/02 17:39:58]

do you need to return anything at all? the result doesn't seem to be used
anywhere in the code..

[riju_, 2015/03/03 09:53:55]

Done.

+}
+
 }  // namespace
 
 
@@ -222,8 +232,36 @@ class DataFetcherSharedMemory::SensorEventSinkMotion
   DISALLOW_COPY_AND_ASSIGN(SensorEventSinkMotion);
 };
 
+class DataFetcherSharedMemory::SensorEventSinkLight
+    : public DataFetcherSharedMemory::SensorEventSink {
+ public:
+  explicit SensorEventSinkLight(DeviceLightHardwareBuffer* const buffer)
+      : buffer_(buffer) {}
+  virtual ~SensorEventSinkLight() {}
+
+ protected:
+  virtual bool UpdateSharedMemoryBuffer(ISensor* sensor,
+                                        ISensorDataReport* new_data) override {
+    double lux;
+    bool has_lux;
+
+    GetSensorValue(SENSOR_DATA_TYPE_LIGHT_LEVEL_LUX, new_data, &lux, &has_lux);

[timvolodine, 2015/03/02 17:39:58]

has_lux does not seem be used after the call. should anything special happen in
case has_lux == false?

[riju_, 2015/03/03 09:53:55]

Done. returning early if valid no lux value is found.

+
+    SetLightBuffer(buffer_, lux);
+
+    return true;
+  }
+
+ private:
+  DeviceLightHardwareBuffer* const buffer_;
+
+  DISALLOW_COPY_AND_ASSIGN(SensorEventSinkLight);
+};
+
 DataFetcherSharedMemory::DataFetcherSharedMemory()
-    : motion_buffer_(nullptr), orientation_buffer_(nullptr) {
+    : motion_buffer_(nullptr),
+      orientation_buffer_(nullptr),
+      light_buffer_(nullptr) {
 }
 
 DataFetcherSharedMemory::~DataFetcherSharedMemory() {
@@ -277,6 +315,20 @@ bool DataFetcherSharedMemory::Start(ConsumerType consumer_type, void* buffer) {
         SetBufferAvailableState(consumer_type, true);
       }
       break;
+      case CONSUMER_TYPE_LIGHT:

[timvolodine, 2015/03/02 17:39:58]

alignment as with above cases

[riju_, 2015/03/03 09:53:55]

Done.

+      {
+        light_buffer_ = static_cast<DeviceLightHardwareBuffer*>(buffer);
+        scoped_refptr<SensorEventSink> sink(
+            new SensorEventSinkLight(light_buffer_));
+        bool sensor_light_available = RegisterForSensor(
+            SENSOR_TYPE_AMBIENT_LIGHT, sensor_light_.Receive(), sink);
+        if (sensor_light_available)

[timvolodine, 2015/03/02 17:39:58]

what's the value of the buffer? should it be initialized to -1?

[riju_, 2015/03/03 09:53:55]

Done.

+          return true;
+
+        // if no sensors are available, fire an Infinity event.
+        SetLightBuffer(light_buffer_, std::numeric_limits<double>::infinity());
+      }
+      break;
     default:
       NOTREACHED();
   }
@@ -293,6 +345,9 @@ bool DataFetcherSharedMemory::Stop(ConsumerType consumer_type) {
     case CONSUMER_TYPE_MOTION:
       motion_buffer_ = nullptr;
       return true;
+    case CONSUMER_TYPE_LIGHT:
+      SetLightBuffer(light_buffer_, -1);

[timvolodine, 2015/03/02 17:39:58]

also light_buffer = nullptr?

[riju_, 2015/03/03 09:53:55]

Done.

+      return true;
     default:
       NOTREACHED();
   }
@@ -368,6 +423,12 @@ void DataFetcherSharedMemory::DisableSensors(ConsumerType consumer_type) {
         sensor_gyrometer_.Release();
       }
       break;
+    case CONSUMER_TYPE_LIGHT:
+      if (sensor_light_.get()) {
+        sensor_light_->SetEventSink(nullptr);
+        sensor_light_.Release();
+      }
+      break;
     default:
       NOTREACHED();
   }